1880.] 



G. Thibaut — On the Silryaprajnafti. 



125 



yishes at evening in the western ocean (same objection as above); others again, 

 lie rises from the eastern ocean, enters at evening into the western ocean, 

 passes during the night through the subterraneous workl, rises again from 

 the eastern ocean. The last opinion mentioned is not very clear and an 

 account of it is therefore not given in this place. 



The third and fourth books contain particulars about tlie tapakshetra, 

 i. e., that jiart of the Jambudvipa which on each day is illuminated by the 

 sun or rather by the two suns. The shape of this tapakshetra the Siirya- 

 prajna^iti compares to that of a kalambuka-flower turned upwards, a com- 

 parison which has to be understood in the following manner. Each of tlie 

 two suns illuminates a sector of the large circle formed by the Jambudvipa. 

 These sectors are, however, not complete, but a piece is cut off from each 

 by Mount Meru which standing in the middle of the circls repels by its 

 own superior radiancy the rays proceeding from the two suns and therefore 

 is not included in the tapakshetra. The interior border of the sectors is 

 thus formed by a part of the circumference of Mount Meru, their outward 

 border by a part of the circumference of the Jambudvipa. Between these 

 two sectors of light there lie two sectors of shade (andhakara) ; whatever 

 part of the Jambudvipa is covered by the two former enjoys day at the 

 time while it is night in the regions covered by the dark sectors. As the 

 two suns revolve these four sectors revolve with them, sweeping over the 

 whole extent of the Jambudvipa and producing alternate day and night in 

 all its parts. The relative magnitudes of the tapakshetra during the differ- 

 ent parts of the year is estimated in accordance with the statements about 

 the relative length of night and day. On the longest day the two suns, 

 moving in the innermost circle, together illuminate three-fifths of the Jam- 

 budvipa, each of them three-tenths ; on the shortest day they illuminate 

 two-tenths each, together two-fifths. On the day after the summer solstice 

 ■when the suns have entered into the second circle, and are moving at a 

 greater distance from the centre, the extent of the tapakshetra decreases 



3 1 3 1 



accordingly, so that it then equals -— = ■- of the 



^ ^ 5 5 X 183 5 915 



whole Jambudvipa only ; the same decrease repeats itself daily up to tlie 



day of the winter solstice when the extent of the illuminated portion of 



the Jambudvipa has reached the minimum stated above. From that period 



it again begins to increase by the same portion daily. From this the 



absolute dimensions of the tapakshetra or, to express it more conveniently, 



of one of the two sectors composing the tapakshetra are easily derived. 



The two straight lines by which it is limited are equal in length to the 



radius of the Jambudvipa less the radius of Mount Meru (50,000 — 5,000 



= 45,000 yojanas). To tliis we find in one pas.sage of the Suryaprajna])ti 



added the j^ixth jiart of the brcadtli of the salt ocean .surroumling the Jam- 



